SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

The 2007 Multiple Primary and Histology Coding Rules present the first site-specific multiple primary and histology rules developed to promote consistent and standardized coding by cancer registrars. See Registrar Training to view recordings and transcripts of the MP/H Rules Breeze-online training sessions.

The 2007 Multiple Primary and Histology Coding Rules contain site-specific rules for lung, breast, colon, melanoma of the skin, head and neck, kidney, renal pelvis/ureter/bladder, benign brain, and malignant brain. A separate set of rules addresses the specific and general rules for all other sites. The multiple primary rules guide and standardize the process of determining the number of primaries. The histology rules contain detailed histology coding instructions. For example, grouping histologic terms, differentiating between general (NOS) terms and specific histologic types and subtypes, and identifying mixed and combination codes are covered. The MP/H Task Force also developed three new data items that complement these rules.